Automatic telephone system



' 1,632,0 June 14, 1927. c. A. MORTON 35 AUTOMATIC TELEPHONE SYSTEM Filed Dec. 1. 1924 Awe a /mr/wAA/arfm I Patented June 14, 1927.

- UNITEDiSiTA CHARLES A. MORTOIiLOF NEW YORK, N. Y., ASSIGNOR TO WESTERN ELECTRIC OOM- PANY, INCORPORATED, 015 NEW YORK, N. Y, A CORPORATION OF NEW YORK.

AUTOMATIC TELEPHONE SYSTEM.

Application fl l ed December 1 1924. Serial No. 753,027. 7

This invention relates to automatic telephone systems, more especially tosuch systems using call charging apparatus,and is particularly adapted for use in conjunction 5 with a metering circuit arrangement for systems of this character.

The object of the inventionis to provide an improved circuit arrangement for automatically operating the charging device asso- 10 ciated with the calling line upon the com- In accordance with this invention, means is provided for reversing the direction of the flow of current in the calling linewhcn the connector is set upon an ordinary line or upon one of a group of ordinary lines, said current reversingmeans being rendered inoperative, however, whenever a connector is set upona free line or upon one of a group of tree lines, it being understood that-whenever the direction of the flow of current applied to the callii'lg station ,is reversed, the call charging mechanism associated with the calling line is operated to charge forthe call.

Referring to the drawing, comprising but a single sheet, Fig. 1 shows a calling subscribers line, a primary line switch, a selector, a connector, and a called subscribers line; and Figs. 2 and 3 show modified. forms of the invention.

Only so much of the circuits are shown as is necessary "to comprehend the invention. It should be understood, however, that this invention may he used in a system such, for

example, asfthe one shown in the patent to icks No. 1,37 9.068, issued May 24, 1921 and Reissue No. 15,762 of Feb. 12, 1924.

It is thoughtthat the invention will be more clearly understood from the detailed description of the operation of the system. \Vhen the subscriber at the calling station 1 removes the receiver to initiate a call, cir-' cuits are closedto operate the line switch or switches as described in said Wicks patent to extend thehcalling line to, the selector S. so that the spring contacts 10, 11and12 will engage the spring contacts 20, 21, and 22., impulse relay, not shown but which'is included in the square designated 5, operates in series with the loop of the calling station 1 and connects ground in a manner not shown, but which is disclosed and described in said icks patent, to the lead 44. Relay 3 is held by way of conductor 44 to this ground and relay 8 operates in parallel with relay'3 to the same ground and functions in a manner hereinafter described. The messageregister 4which is in parallel with relay 3 does not operate at this time. The dial '(not shown) 1 at the calling station 1 is now operated causing the selector setting mechanism (not shown but included in the square designated 5) to operate in the well-knownmanner and set the brushes 30, 31, and 32o'f the selector S upon the terminals of an idle trunk leading to one of the switches of the next switclrgroup. WVhileit should be unv v derstood that severalv such switches may be inserted between the selector nector C without 3 and the condeparting from the spirit of this invention, we will assume, that the brushes 30, 31, and 32 are now resting upon the terminals 40, 41, and 42 associated with the'j'c'onnector C. Under these conditions, a cir'cuitincluding the impulse relay 13, polarize'd relay6, and the loop at the calling station 1 will be closed and relay 13. will oper I ate closing an obvious circuit to operate relay 15. Relay 6 which is polarized, will not operate at this time due to the direction of the flow of current in its winding.

hen the dial at the calling station 1 is operated and released. in accordance with the tens digit of the called number, the. circuit including the impulserelay 13 is interrupted at the calling station 1 and relay 13 follows these interruptions or impulses. When relay 13 releases, a circuit is closed to operate the primary magnet17 and relay 16 in series byway of contact 37, right-hand armature and front contact of relay 15, armature and back contact of relay 13 to ground. The

primarymagnet 17 and relay: 16 operate over this circuit, the -former causing the brushes 34, 50, 51, and 52 secured to the brush shaft (not shown) to be'stepped one step in the primary During this first step, the contact 37 ofthe off-normal .contact springs ON -is opened and thef'co'ntact 38' is closed. 'During each subsequent impulse of the impulse train,

relay 13 rad-the primary magnet: it

movement of the connector 0.

again operates continuing the primary movement of the switch shaft. The stepping circuit may now be traced from battery, wimling of magnet 17, through the winding and front contact of relay 16, contact 38, right. contactsof relays 15 and 123 to ground. Relays 15 and 16 which are slow to release remain. operated during the impulse period. At the end of the impulse train, relay 16' releases preparing a circuit for the secondary magnet 18 which operates as hereinafter described. The brush 3a is now resting upon one 01 the terminals 35, 36, etc. of the commutator X.

The dial is again operated and released in accordance with the units digit of the called line, which we will assume to be the station 2, in which case the digit 1 is dialed. The secondary magnet 18 is 110w operated under control of impulse relay 13 and slow relays 15 and 16, relay 15 being'operated and relay 16 released. The circuit for the secondary magnet may be traced from hattery through the winding of said magnet, back contact of relay 16, contact 38, to ground through the right contacts of relays 15 and 13. The secondary magnet 18 perates the switch shatt carrying the brushes 34;, 50, 51, and 52 in the secondary movement of the switch and brushes 50, 51, and 52 will come to rest upon the terminals 60, 61, and 62, respectively, ofthe called line 2. The connector switch 0 will test the busy or idle condition of the called line in a manner, not shown, but which is disclosed and described in the patent to Nicks cited. \Ve will assume thecalled station 2 is idle, in which case, ground will be connected by way oi'brush 52 and terminal (32 to operate relay (51 through its right winding.

Ringing current is now connected to the called line in a manner, not shown, but which is disclosed and described in said lVicks patent. \Ve will assume the called station 2 to be an ordinary line, that is, a line for calls to which the calling station is to be charged. In this event, the brush will be resting upon the torn'iinal 36 or some other similar terminal which is connected to ground. It will be remcn'ibcred that the brush 3 1 came to rest upon one of these terminals at the end of the primary movement of the connoctor C and it should be understood that the brush 31 is so arranged that it remains in contact with the terminal 36 or some similar terminal during the secondary movement of the switch and until the connector C is restored to normal. It should be further understood that all the lines upon the level selected will be ordinary lines, the same as the called line 2, the lines to which the connector C has access being segregated in groups depending upon whether they are ordinary lines or free lines.

lVhen the receiver is removed at the called station 2, in response to the ringing signal, a circuit is closed including the windings of relay 2} and the loop of the called station 2 operating relay 2 1. lVith the brush 34; resting upon grounded terminal, for example 36, an obvious circuit is closed to operaterelay 141-. The relay 14 operated reverses the direction of the flow of current supplied tl'n'ough the windings of relay 13 to the calling station 1. Relay 6, which is included in this circuit, is polarized and responds to said current reversal. The operation of relay 6 closes a circuit by way of its armature and front contact, brush 32, to ground under control of relay 15, to operate relay 7. Relay 7 operated locks by way of brush 32 under control of relay 15. The operation of relay 7 opens at its right-hand armature and back contact the circuit previously established to operate slow-to-release relay 8, and connects the booster battery 9 by way of terminal and brush 12 to the winding of the meter 4 which operates to. charge the call. Relay 3 remains operated under this circuit condition. lVhen slow-to-release relay 8 releases, the booster battery 9 is dirconected from the meter 1 and the relay 3, but the meter and relay remain operated in parallel by way of 12, 22, left-hand inner armature and front contact of relay 7, normal contacts of relay 8, 4A, 32, 12, armature and front contact of relay to ground.

Assume, however, that the connector C instead of being set upon the terminals (50, 61, and 62 associated with the called line 2, had been set upon the terminals associated with a tree line then the brush 34; would have been resting upon the terminal 35 or some similar non-grounded terminal. In this event, when the called station answered the circuit to operate relay 14: would not have been closed; hence, the direction of the flow of current supplied through the wind ings of relay 13 to the. called line, would have remained unchanged and the polarized relay (5 would have remained inoperative, hence the circuit to operate the meter 4. would not have been closed.

In any event, when the receiver is re placed upon the switchhook at the calling station 1, the impulse relay 1 releases, opening the circuit through the winding of slowto-release magnet 15, which likewise releases, and the release magnet 11) is operated over a circuit (not shown) to restore the connector C to normal.

In Fig. 2, an alternative arral'igei'nent is shown, whereby it becomes unnecessary to maintain the brush 33 incontact with the terminals 26, 27, etc., of the COIDlYllltltl't'H', during the secondary movement of the con-- nector C. An additional relay is pro vided which operates as soon as relay 16 releases at the end of the primary movement providing the brush 33 is resting upon a grounded terminal. In case relay 25 0 erates, it closes a locking circuit by way of its right-hand armature and front contact, contact 23, and the armature of the release magnet 19, to ground. During the secondary movement of the connector, brush 33 may break contact with the terminal of the commutator without affecting theoperation of the connector in any way. When the receiver is removed from the switchhook at the called station, relay 24 operates as before. Relay 14;, however, will not operate unlessrelay 25 is locked up, since the closing of the operating circuit for relay 14 depends upon the operated condition of relay 25. Relay 14 functions in the manner previously described in connection with the description of Fig. 1.

Fig. 3 shows another modification of Fig. l which may be used when it is desirable to mingle ordinary lines and free lines indiscriminately at the connector bank instead of segregating the free lines from the ordinary lines, as shown in Figs. 1 and 2. \Vhenever it is desired to mixthe free and the ordinary lines indiscriminately, it is necessary to furnish an extra brush and an additional row of contacts in the terminal bank, as indicated in Fig. 3. The commutator X and brush 34, however, are not required. The extra terminal associated with the ordinary lines is connected to ground, as indicated at 7 3, while the extra terminal associated with the free lines remains ungrounded, as indicated at 63. When the called station answers and relay 24 operates in the manner previously described, relay 14 will operate providing the brush 53 is resting upon a grounded terminal such, for example, as ter- Dlll'litl. 73, but will not operate whenever the brush 53 is resting upon a non-grminded ter minal such, for example, as terminal 63. Relay 14, functions to control the reversing of the flow of current in the calling line in the manner previously described in connection with the description of Fig. 1.

lVhile for purposes of illustration, the invention has been shown in conjunction with a calling'line equipped with a meter, it is not so limited, but may be used to control the coin box mechanism at a calling station. Lines of this type are disclosed in the patent to'Stokely, No. 1,452,323 issued April 17, 1923. I

What is claimed is:

1. In a telephone system, a calling line,

alled lines, an automatic switch for interconnecting the same, means in said automatic switch for supplying talking battery to said calling line, a relay for-reversing the direction of the flow of current in the calling line, a local circuit for said'relay, means dependent upon the classification of the called line for either extending or preventing the extension of said local circuit, andmeans responsive to the called line in answering for closing said local circuit to operate said relay.

i 2. In a telephone system, a calling line, called lines an automatic switch for interconnecting the same, means for producin a.

flow ofcurrent in said calling line, a relay operable to reverse the direction of said cur -x rent flow, a local circuit for said relay, a supervisory relay,.means dependent upon the classification of the called line for extending said local circuit to said SUPGIVISOIY'IBlfl-Y, and means responsive to the called line in answering for operatingsaid'supervisory relay "to close said local circuit.

4. In a telephone system, a calling line, I

called linesclassifiable as free or as charge lines, an automatic switch for-establishing a talking connection between said line's, means in said automatic switch forproducing a flow of current in said calling line, means for reversing the direction of said current flow, means responsive to the setting of the switch on a charge linefor preparing an operating circuit for said current reversing means independent of said talking connection, and means in the switch responsive to the called linein answering for completing the circuit of said current reversing means.

5. In a telephone system, a calling line, an automatic switch, called lines appearing in Said switch asfree lines and charge lines, means for operating said switch to establish a talking connection between the calling line and a called line, a group. of contacts having different electrical conditions thereon for discriminating between a free and a charge line, means for producing a current flow in the calling line, a relay for reversin the direction of'said current flow, a circult for said relay, separate from said talking connection, a brush coacting with said contacts to close said circuit when the switch selects a charge line and to maintainthe circuit open when the switch selectsa tree line, and a message register responsive to a reversal of current. g

In-witness whereof,,I hereunto subscribe my name this 21st day of November A. D., 1924.

' CHARLES A. MORTON. 

